Smoking articles with nanocellulose barrier

ABSTRACT

A smoking article includes a lighting end longitudinally opposite a filter end that includes a filter. A fluid-releasing element is disposed longitudinally between the lighting end and filter end. A paper material circumscribes a portion of the smoking article, and a nanocellulose barrier disposed upon at least one surface or interface within the smoking article is provided, effective to control passage of fluid through the paper material.

TECHNICAL FIELD

The present invention relates to products made or derived from tobacco, or that otherwise incorporate tobacco, and are intended for human consumption. Certain embodiments of the present invention relate to smoking articles including flavor-releasing filter components. More particularly, embodiments of the present invention include structures, methods, and devices related to barrier formation on wrapping materials (including tipping and plug wrap materials) of smoking articles.

BACKGROUND

Popular smoking articles, such as cigarettes, have a substantially cylindrical rod shaped structure and include a charge, roll or column of smokable material such as shredded tobacco (e.g., in cut filler form) surrounded by a paper wrapper thereby forming a so-called “smokable rod” or “tobacco rod.” Normally, a cigarette has a cylindrical filter element aligned in an end-to-end relationship with the tobacco rod. Typically, a filter element comprises cellulose acetate tow plasticized using triacetin, and the tow is circumscribed by a paper material known as “plug wrap.” A cigarette can incorporate a filter element having multiple segments, and one of those segments can comprise activated charcoal particles. See, for example, U.S. Pat. No. 6,537,186 to Veluz; PCT Publication No. WO 2006/064371 to Banerjea; and U.S. Pat. App. Pub. No. 2007/0056600, to Coleman III, et al.; each of which is incorporated herein by reference. Typically, the filter element is attached to one end of the tobacco rod using a circumscribing wrapping material known as “tipping paper.” It also has become desirable to perforate the tipping material and plug wrap, in order to provide dilution of drawn mainstream smoke with ambient air. Examples of tipping materials are disclosed in, for example, U.S. Pat. No. 7,789,089 to Dube et al., and U.S. Pat. App. Pub. Nos. 2010/0108081 to Norman, and 2010/0108084 to Norman, each of which is incorporated herein by reference. See also, for example, the types of cigarette filter element formats, configurations and designs set forth in U.S. Pat. No. 5,025,814 to Raker; and U.S. Pat. App. Pub. Nos. 2007/0215167, to Crooks et al. and 2010/0108081 to Joyce et al., each of which is incorporated herein by reference. Descriptions of cigarettes and the various components thereof are set forth Tobacco Production, Chemistry and Technology, Davis et al. (Eds.) (1999). A cigarette is employed by a smoker by lighting one end thereof and burning the tobacco rod. The smoker then receives mainstream smoke into his/her mouth by drawing on the opposite end (e.g., the filter end) of the cigarette.

The sensory attributes of cigarette smoke can be enhanced by applying additives to tobacco and/or by otherwise incorporating flavoring materials into various components of a cigarette. See, Leffingwell et al., Tobacco Flavoring for Smoking Products, R. J. Reynolds Tobacco Company (1972). For example, one type of tobacco flavoring additive is menthol. See, Borschke, Rec. Adv. Tob. Sci., 19, p. 47-70, 1993. Various proposed methods for modifying the sensory attributes of cigarettes include certain filter elements that may be used for adding flavor to the mainstream smoke of those cigarettes. U.S. Pat. No. 6,761,174 to Jupe et al. proposes the placement of adsorbent and flavor-releasing materials in a cigarette filter. U.S. Pat. No. 6,584,979 to Xue et al. proposes the placement of fibers containing small particle size adsorbents/absorbents in the filter. U.S. Pat. No. 4,941,486 to Dube et al. and U.S. Pat. No. 4,862,905 to Green, Jr. et al., which are incorporated herein by reference, propose manners and methods for the placement of a flavor-containing pellet in each cigarette filter. Other representative types of cigarette filters incorporating flavoring agents are set forth in U.S. Pat. No. 3,972,335 to Tiggelbeck et al.; U.S. Pat. No. 4,082,098 to Owens, Jr.; U.S. Pat. No. 4,281,671 to Bynre; U.S. Pat. No. 4,729,391 to Woods et al.; U.S. Pat. No. 4,768,526 to Pryor; U.S. Pat. No. 5,012,829 to Thesing et al.; U.S. Pat. No. 5,387,285 to Rivers; and U.S. Pat. No. 7,074,170 to Lanier, Jr. et al.; and each of which is incorporated herein by reference. See, also, the types of cigarette filter technologies that are discussed in the background art section set forth in U.S. Pat. No. 7,836,895 to Dube et al.; which is incorporated herein by reference.

It would be highly desirable to provide a smoker with the ability to enhance his/her smoking experience, such as can be accomplished by providing a filtered cigarette including a filter element having particular design features. That is, it would be desirable to provide a cigarette including filter components that are employed in a manner such that the filter element is aesthetically pleasing. It also would be desirable to provide such a filter element including selected design features that can be modified or otherwise controlled. In addition, it would be desirable to provide a filter element for a cigarette that is capable of enhancing the sensory attributes of the mainstream smoke (e.g., by flavoring the mainstream smoke) produced by that cigarette. Flavor enhancing materials disposed in a filter may include liquid or other flowable composition, such that it may be desirable to provide one or more barrier structures to prevent flowable material from passing through plug wrap and/or tipping material disposed around the filter.

BRIEF SUMMARY

In one aspect, embodiments disclosed herein may include smoking article with a lighting end longitudinally opposite a filter end that includes a filter, a fluid-releasing element disposed longitudinally between the lighting end and filter end, a paper material circumscribing a portion of the smoking article, and a nanocellulose barrier disposed upon at least one surface or interface within the smoking article and effective to control passage of fluid through the barrier. In certain embodiments, nanocellulose may be disposed on an inward-facing and/or outward-facing surface of plug wrap material circumscribing the filter. In those and/or other embodiments, nanocellulose may be disposed on an inward-facing surface of tipping material circumscribing filter material and/or plug wrap material.

In other aspects, embodiments disclosed relate to a smoking article with a lighting end that includes a tobacco rod disposed longitudinally opposite a filter end that includes a filter, a fluid-releasing element (which may be embodied as a rupturable capsule) disposed within the filter, a paper wrapping material circumscribing the tobacco rod, a plug wrap material circumscribing the filter, and a nanocellulose barrier circumscribing the filter, which is effective to control passage of fluid through the barrier.

In still other aspects, presently disclosed embodiments relate to a smoking article with a lighting end that includes a tobacco rod disposed longitudinally opposite a filter end that includes a filter, a fluid-releasing flavor capsule disposed within the filter, a paper wrapping material circumscribing the tobacco rod, a plug wrap material circumscribing the filter, a nanocellulose barrier coating disposed upon at least one surface of the plug wrap circumscribing the filter, said barrier effective to control passage of fluid through the barrier, and tipping material circumscribing the plug wrap materials.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an exploded perspective of smoking article, showing the smokable material, the wrapping material components, and the filter element;

FIG. 2 shows a longitudinal cross-section view of a filter element incorporating an adsorbent material therein according to one embodiment of the present invention;

FIG. 3 is a longitudinal cross-section view of a smoking article having the form of a cigarette, showing smokable material, wrapping material components, and a filter element including a releasable material;

FIG. 4 is a longitudinal cross-section view of a smoking article having the form of a cigarette, showing a smokable-material lighting end, heating and aerosol generating segments, wrapping material components, and a filter element including a releasable material; and

FIG. 5 is a longitudinal cross-section view of a smoking article having the form of a cigarette, showing heating and aerosol generating segments, wrapping material components, and a filter element including a releasable material.

DETAILED DESCRIPTION

Various embodiments are described below with reference to the drawings. The relationship and functioning of the various elements of the embodiments may better be understood by reference to the following detailed description. However, embodiments are not limited to those illustrated in the drawings. It should be understood that the drawings are not necessarily to scale, and in certain instances details may have been omitted that are not necessary for an understanding of embodiments disclosed herein, such as—for example—conventional fabrication and assembly.

The invention is defined by the claims, may be embodied in many different forms, and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey enabling disclosure to those skilled in the art. As used in this specification and the claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Reference to “dry weight percent” or “dry weight basis” refers to weight on the basis of dry ingredients (i.e., all ingredients except water).

A typical smoking article in the form of a cigarette 174 is illustrated with reference to FIG. 1. The cigarette 174 includes a generally cylindrical rod 186 of a charge or roll of smokable filler material 188 contained in a circumscribing wrapping material 190 of the present invention. The rod 186 is conventionally referred to as a “tobacco rod”. The ends of the tobacco rod are open to expose the smokable filler material. A lighting end 195 is disposed at one end of the tobacco rod 186, and a filter element 100 is shown at the other end. The cigarette 174 is shown as having a band 102 printed on wrapping material 190, and that band entirely circumscribes the cigarette rod in a direction transverse to the longitudinal axis of the cigarette. That is, the band 102 provides a cross-directional region relative to the longitudinal axis of the cigarette 174. The band 102, if present, may be applied to the inner surface of the wrapping material 190 (i.e., facing the smokable filler material), and/or may be applied to the outer surface of the wrapping material 190. Although the cigarette 174 shown in FIG. 1 has wrapping material having one band, the cigarette also can include wrapping material having two, three, or more spaced bands. The band 102 may include a water-based coating formulation that affects ignition potential of the coated wrapping paper portion. Certain examples of coatings are described in U.S. Pat. No. 6,929,013 to Ashcraft et al., U.S. Pat. No. 6,976,493 to Chapman et al., U.S. Pat. No. 6,997,190 to Stokes et al., and U.S. Pat. No. 7,600,518 to Ogelsby et al., each of which is incorporated by reference herein.

The cigarette 174 commonly includes a filter element 100 or other suitable mouthpiece positioned adjacent one end of the tobacco rod 186 such that the filter element and tobacco rod are axially aligned in an end-to-end relationship, abutting one another. Filter element 100 has a generally cylindrical shape, and the diameter thereof is essentially equal to the diameter of the tobacco rod. The ends of the filter element are open to permit the passage of air and smoke therethrough. The filter element 100 includes filter material 105 (e.g., plasticized cellulose acetate tow) that is overwrapped along the longitudinally extending surface thereof with circumscribing plug wrap material 106. The filter element 100 can have two or more filter segments, and/or flavor additives incorporated therein, as discussed—for example—below with reference to FIGS. 2-5.

The filter element 100 is attached to the tobacco rod 186 by tipping material 108 which circumscribes both the entire length of the filter element and an adjacent region of the tobacco rod. The inner surface of the tipping material 108 is secured to the outer surface of the plug wrap 106 and the outer surface of the wrapping material 190 of the tobacco rod using a suitable adhesive. A ventilated or air-diluted smoking article may be provided with an air-dilution means, such as a series of perforations 110, each of which extends through the tipping material and underlying plug wrap.

Certain types of smoking articles may include filter elements that incorporate objects, such as breakable capsules. Various components of such filter elements, as well as equipment and techniques for manufacturing such filter elements, are set forth, for example, in U.S. Pat. No. 7,479,098 to Thomas et al.; U.S. Pat. No. 7,793,665 to Dube et al.; U.S. Pat. No. 7,833,146 to Deal; U.S. Pat. No. 7,836,895 to Dube et al.; and U.S. Pat. No. 7,972,254 to Stokes et al.; U.S. Pat. Pub. Nos. 2008/0142028 to Fagg; 2009/0050163 to Hartmann et al.; 2009/0090372 to Thomas et al.; 2009/0194118 to Ademe et al.; 2010/0184576 to Prestia et al.; 2010/0236561 to Barnes et al.; 2011/0053745 to Iliev et al.; and PCT App. Pub. No. WO 03/009711 to Kim; each of which is incorporated herein by reference. Exemplary capsules can be of the type employed commercially in cigarettes marketed under the brand name Camel Crush® by R. J. Reynolds Tobacco Company.

In some instances, a filter element 26 may be configured as shown in FIG. 2, wherein the filter includes a first filter segment 32 positioned adjacent one end of the charge of smokable material, embodied here as a tobacco rod 12. The first filter segment 32 includes filter material 40 (e.g., cellulose acetate tow impregnated with plasticizer, such as triacetin). In other instances, the filter element 26 may not be divided into segments, such as shown in FIG. 3. With continuing reference to FIG. 2, an adsorbent material/particulate or one or more objects configured for actuatable release of flavor (e.g., a rupturable or breakable capsule), generally designated here as object/material 50 may be inserted within the filter material 40 of the first segment. In certain embodiments where a carbonaceous material is used as an adsorbent material 50, at least a portion of the carbonaceous material, and typically virtually all of the carbonaceous material, is in intimate contact with an effective amount of a mixture of polyol ester (e.g., triacetin) and polyol (e.g., propylene glycol). If desired, the filter element also can be incorporate other components that have the ability to alter the properties of the mainstream smoke that passes throughout the filter element. See, for example, U.S. Pat. Application Publication Nos. 2004/0237984 to Figlar et al.; 2005/0268925 to Schluter et al.; 2006/0130861 to Luan et al.; and 2006/0174899 to Luan et al., which are incorporated herein by reference.

The filter element 26 may also include a second filter segment 36 longitudinally disposed relative to the first segment 32 and positioned at the extreme mouth end of a cigarette. The second filter segment 36 includes filter material 48 (e.g., cellulose acetate tow impregnated with plasticizer, such as triacetin) that is over-wrapped along the longitudinally extending surface thereof with circumscribing plug wrap material 28. The second filter segment 36 may be substantially free of adsorbent and breakable or rupturable capsules, meaning that such additives are not visible when viewing the extreme mouth end of the filter element 26.

The filter element 26 is circumscribed along its outer circumference or longitudinal periphery by a layer of outer plug wrap 28. The outer plug wrap 28 overlies each of the first filter segment 32 and the second filter segment 36, so as to provide a combined, two-segment filter element.

The filter element 26 is attached to the tobacco rod 12 using tipping material 46 (e.g., essentially air impermeable tipping paper), that circumscribes both the entire length of the filter element 26 and an adjacent region of the tobacco rod 12. The inner surface of the tipping material 46 is fixedly secured to the outer surface of the plug wrap 28 and the outer surface of the wrapping material 16 of the tobacco rod, using a suitable adhesive (and/or potentially including a nanocellulose fluid-barrier), whereby the filter element and the tobacco rod are connected to one another. See also the tipping materials and configurations set forth in U.S. Pat. Publication No. 2008/0029111 to Dube et al., which is incorporated by reference herein.

A ventilated or air diluted smoking article can be provided with an optional air dilution mechanisms, such as a series of perforations 30, each of which extend through the tipping material and plug wrap. The optional perforations 30, shown in FIG. 3, can be made by various techniques known to those of ordinary skill in the art, such as laser perforation techniques. Alternatively, so-called off-line air dilution techniques can be used (e.g., through the use of porous paper plug wrap and pre-perforated tipping paper). For cigarettes that are air diluted or ventilated, the amount or degree of air dilution or ventilation can vary. Frequently, the amount of air dilution for an air diluted cigarette is greater than about 10 percent, generally is greater than about 20 percent, often is greater than about 30 percent, and sometimes is greater than about 40 percent. Typically, the upper level for air dilution for an air diluted cigarette is less than about 80 percent, and often is less than about 70 percent. As used herein, the term “air dilution” is the ratio (expressed as a percentage) of the volume of air drawn through the air dilution means to the total volume and air and smoke drawn through the cigarette and exiting the extreme mouth end portion of the cigarette.

The wrapping material 16 of the tobacco rod 12 may include a wide range of compositions and properties. The selection of a particular wrapping material will be readily apparent to those skilled in the art of cigarette design and manufacture. Tobacco rods can have one layer of wrapping material, or tobacco rods can have more than one layer of circumscribing wrapping material, such as is the case for the so-called “double wrap” tobacco rods. Exemplary types of wrapping materials, wrapping material components and treated wrapping materials are described in U.S. Pat. No. 5,220,930 to Gentry; and US Pat. Application Pub. Nos. 2004/0129281 to Hancock et al.; and 2005/0039764 to Barnes et al.; and PCT Application Pub. No. WO 2004/057986 to Hancock et al.; and PCT Application Pub. No. WO 2004/047572 to Ashcraft et al.; which are incorporated herein by reference in their entireties.

During use, the smoker lights the lighting end 18 of the cigarette 10 using a match or cigarette lighter. As such, the smokable material 12 begins to burn. The mouth end 20 of the cigarette 10 is placed in the lips of the smoker. Thermal decomposition products (e.g., components of tobacco smoke) generated by the burning smokable material 12 are drawn through the cigarette 10, through the filter element 26, and into the mouth of the smoker. During draw, certain amount of certain gaseous components of the mainstream smoke may be removed from the mainstream smoke or neutralized within the filter element 26. Filters incorporating adsorbent material, such as carbonaceous filter components (e.g., activated charcoal particles) have the capability of capturing a wide range of mainstream tobacco smoke vapor phase components. If desired, prior to, during, or after the smoking experience, the smoker can optionally squeeze the filter element. As a result, at least a portion of breakable capsule(s) in the filter can be broken, and hence release a flavoring agent contained therein, which may be in particulate and/or liquid form. The cigarette 10 may, in some embodiments, include one or more band(s) 22 (e.g., a printed coating including one or more film-forming agents, such as starch, ethylcellulose, or sodium alginate) applied to the wrapping material 16 to provide a low-ignition-propensity region(s) when that band mostly or wholly circumscribes the tobacco rod in a direction transverse to the longitudinal axis of the cigarette.

The dimensions of a representative cigarette 10 can vary. Preferred cigarettes are rod shaped, and can have diameters of about 7.5 mm (e.g., circumferences of about 20 mm to about 27 mm, often about 22.5 mm to about 25 mm); and can have total lengths of about 70 mm to about 120 mm, often about 80 mm to about 100 mm. The length of the filter element 30 can vary. Typical filter elements can have total lengths of about 15 mm to about 40 mm, often about 20 mm to about 35 mm. For a typical dual-segment filter element, the downstream or mouth end filter segment often has a length of about 10 mm to about 20 mm; and the upstream or tobacco rod end filter segment often has a length of about 10 mm to about 20 mm.

As illustrated in FIG. 2, one filter element 26 that may be formed in accordance with the present disclosure includes multiple, longitudinally-extending segments. Each segment can have varying properties and may include various materials capable of filtration or adsorption of particulate matter and/or vapor phase compounds from the mainstream smoke. Typically, the filter element may include 2 to 6 segments, frequently 2 to 4 segments. In some instances, the filter element 26 may include a mouth end segment and a tobacco end segment, with the tobacco end segment comprising a dispersed adsorbent material 50 and a flavoring agent 52.

As shown in FIG. 2, the filter element may incorporate an adsorbent material/particulate or other object 50. An adsorbent material 50 may be a material with relatively high surface area capable of adsorbing smoke constituents without a high degree of specificity, or a material that adsorbs certain compounds with a greater degree of specificity, such as an ion exchange resin. Exemplary types of adsorbent material may include activated carbon, a molecular sieve (e.g., zeolites and carbon molecular sieves), clay, an ion exchange resin, activated alumina, silica gel, meerschaum, and combinations thereofny adsorbent material, or mixture of materials, that has the ability to alter the character or nature of mainstream smoke passing through the filter element may be used.

As shown, for example, in FIG. 3, an adsorbent or other material may be included in a carrier 55 within a filter element 26 (or a continuous filter rod before longitudinal severance thereof to form multiple filter elements 26). Selection of a suitable carrier material 55 may facilitate, for example, improved production by more effectively and efficiently inserting the now “captive” adsorbent material into the filter element 26. That is, the adsorbent material (or another non-adsorbent material) is carried by the carrier material 55 upon insertion thereof into the filter element 26. In some embodiments, the carrier material 55 may be in the form of, for example, a pellet, a capsule, a tube, a continuous elongate structure, a continuous strip, a strand, or any like structure capable of receiving and “holding captive” a desired material so as to facilitate insertion thereof into the filter element 26. In some embodiments, individual or multiple forms of a carrier 55 may be inserted into the filter element 26. For example, individual or multiple capsules, tubes, pellets, etc. or combinations thereof may be inserted into the filter element 26 in accordance with various aspects of different embodiments. In one embodiment, the carrier 55 may be embodied as a rupturable or otherwise breakable capsule containing a flowable material (which may, for example, include flavorant material in a fluid, gel, or other flowable form). Various embodiments may include methods and structures disclosed in U.S. Pat. No. 7,740,019 to Nelson et al.; U.S. Pat. No. 7,794,665 to Dube et al. and U.S. Pat. No. 8,079,369 to Andresen et al., each of which is incorporated herein by reference.

After insertion of a carrier 55 into the continuous rod of filter material, an adsorbent or other material contained therein may be released from the carrier and into the filter material. For example, the carrier 55 may be dissolved, disintegrated, degraded, or otherwise destroyed so as to release and/or disperse the adsorbent material 50 into the filter material so as to allow an adsorbent material 50 to have the desired effect on the mainstream smoke drawn through the filter element. The release of the adsorbent material into the filter material may occur before or after the continuous rod has been severed into filter segments (e.g., filter element 26). Such release can occur during the manufacturing process or, in some instances, may be effectuated by the smoker prior to smoking the smoking article. In some instances, various forms of the adsorbent or other material (i.e., strands, beads, pellets, capsules, or combinations thereof) may be disposed in a closed cell foam as a carrier material 55, wherein, once inserted into a filter element 20, may be irradiated or heated to break down the foam and release the adsorbent or other contained material therefrom. Alternately, a carrier material 55 may comprise an open-cell foam, wherein, for example, air and/or physical force may be used to release the adsorbent material 50 once the object is inserted into the filter element 20. In these or other embodiments, a carrier material 55 may be provided, for example, in the form of a breakable capsule, a “capsule-in-capsule,” or a strand, formed of a water-soluble or other liquid-soluble polymer and configured to carry an adsorbent or other material (such as, e.g., a flavorant material). Such a soluble polymer may comprise, for example, polylactic acid, polyvinyl alcohol (PVA), starches and/or starch-based polymers, carrageenans, polyvinyl acetate, hydroxypropylcellulose, pullulan, carboxymethylcellulose and its salts (i.e., alkali metal salts), alginates and their salts, gelatin, and/or any other suitable polymers or combinations thereof.

The carrier 55 may be hollow, such as a breakable capsule that may carry a payload incorporating a compound that is intended to introduce some change to the nature or character of mainstream smoke drawn through that filter element (e.g., a flavoring agent). That is, the shell of hollow object 55 may be ruptured at the discretion of the smoker to release the object payload. Highly preferred objects are capable of releasing the agent at the command of the user. For example, a preferred breakable hollow object containing an adsorbent material such as a liquid payload is resistant to the release of the payload until the time that the smoker applies a purposeful application of physical force sufficient to rupture the hollow object. Typically, a filter material, such as cellulose acetate tow, is generally absorbent of liquid materials of the type that comprise the payload, and the released payload components will undergoing wicking (or otherwise experiencing movement or transfer) throughout the filter element.

In embodiments where a capsule or other breakable container 50 and/or 55 of a releasable adsorbent or other material is provided, such material may be in a liquid or other flowable form. In such embodiments, it may be desirable to decrease the likelihood that the released material will wick, seep, or otherwise travel through the plug wrap and tipping paper overlying the filter material containing it (e.g., where it would potentially directly contact a user's lips, fingers, or other external object). Specialized liquid-barrier plug wrap papers have been used for this purpose in some products. However, some liquid-barrier plug wrap papers may be more costly than standard plug wrap. For at least this reason, it may be desirable to provide lower-cost solutions using standard plug wrap paper materials.

One such solution may be to apply a barrier material to plug wrap paper, tipping material, and or the wrapping material used to circumscribe a tobacco rod. Barrier materials of the present disclosure may include nanocellulose materials. Nanocellulose or microfibrillated cellulose is a material composed of nanosized cellulose fibrils with a high aspect ratio (length to width ratio), such that the length of the fibers is at least 10× and often 100× their width or more. Typical nanocellulose fibers are tens of nanometers to about 1 to about 2+ micrometers in length and about 5 to about 20 nanometers in diameter. Nanocellulose is a pseudo-plastic material and exhibits a thixotropic property of certain gels that are thick (viscous) under normal conditions, but that exhibit desirable flow characteristics over time when shaken or agitated. These properties are particularly desirable for coatings. The crystalline form is light weight, non-toxic, highly absorbent with very high tensile strength. Nanocellulose is generally produced from wood pulp cellulosic source materials. Nanocellulose has a wide range of known applications, from cleaning of oil spills to production of children's toys. Nanocellulose can be used in pharmaceutical, food and medical industries. In food products, nanocellulose can be used as flavor carriers and suspension of stabilizers. When used in paper products for the present embodiments, nanocellulose helps to improve the fiber to fiber bond strength and acts as a barrier.

A nanocellulose barrier coating may be applied online or offline, in an aqueous or non-aqueous carrier or solvent. “Online application” refers to applying a nanocellulose barrier coating during the process of forming a smoking article or components thereof. In such a process, the material is dynamically applied in line with other assembly steps. So, for example, a nanocellulose barrier coating may be applied to the interface between filter material and plug wrap during assembly of a filter. This may be done by applying nanocellulose barrier coating material to the external surface of the filter material and/or to the filter-material-facing surface of the plug wrap. Alternatively, or in addition, the nanocellulose barrier coating material may be applied to the external-facing surface of the plug wrap material and/or to the inward-facing surface of overlying tipping material (e.g., in an interface therebetween). Structures and processes for applying material as described here are known in the art and may be understood, for example, with reference to U.S. patent application Ser. Nos. 13/338,647 and 13/338,654, both to Ademe, each of which is incorporated by reference herein. “Offline application” refers to the applying the nanocellulose barrier material to plug wrap, tipping material, wrapping material, and/or another material that is not used until a later time and/or in a different location than when/where the material was applied.

For example, nanocellulose may be applied using one of these (or another) technique(s) and a manner providing a coating of about 1 to about 5 gsm (grams/meter²). In one example, a standard (e.g., about 27 gsm basis weight) non-porous plug wrap may be coated with nanocellulose at a density of about 3 gsm. This coating may be applied to the face of the plug wrap that will contact filter tow and will provide an effective barrier for preventing passage therethrough of liquid released from a rupturable capsule disposed within the filter tow. Properties of nanocellulose are described, for example, in Enzymatic Hydrolysis Combined with Mechanical Shearing and High-Pressure Homogenization for Nanoscale Cellulose Fibrils and Strong Gels by Pääköet al. Biomacromolecules, 2007, 8 (6), pp 1934-1941. Nanocellulose materials may be obtained from, for example, JRS J. Rettenmaier & Söhne GmbH+Co. KG (Rosenberg, Germany) or Celluforce (Montreal, Quebec, Canada).

Whether applied online or offline, and whether applied to one or both of inward-facing and outward-facing surfaces of paper material (e.g., plug wrap, tipping material, tobacco rod wrapping material), the nanocellulose will form an effective fluid barrier. When used on tipping material and/or plug wrap material, the barrier will be effective in preventing a flavorant or other material released from a capsule or other fluid-containing modality in/on the filter from flowing or otherwise passing through the overlying paper material. When used in bands or other patterns on wrapping material for circumscribing a tobacco rod, the nanocellulose forms an effective barrier against passage of air. Stated differently, a nanocellulose barrier may be distributed on wrapping material around a tobacco rod in a manner restricting airflow therethrough so as effectively to limit combustion of the tobacco rod in the absence of air being drawn through the tobacco rod (e.g., by a user/smoker). The formation of such bands and other patterns is known in the art for providing regions on wrapping material commonly referred to as fire-safe-cigarette (FSC) or low-ignition-propensity (LIP) papers. See, e.g., PCT App. Publ. No. WO2011/144701A1 to Dumas et al. However, the present disclosure is novel with respect to using nanocellulose to provide this liquid barrier feature for filter-covering materials.

Whether in online or in offline applications, the nanocellulose may be applied using standard printing techniques (gravure, flexographic, etc.), spray-application techniques, and any other techniques currently known or yet to be developed for applying coatings to papers used in smoking articles. Single-layer coating and/or multilayer coating of nanocellulose may be applied using such techniques. Examples of techniques for applying coatings to smoking article paper components include those disclosed in U.S. Pat. No. 6,976,493 to Chapman et al. and U.S. Pat. No. 7,237,559 to Ashcraft et al., in U.S. Pat. App. Pub. No. 2005/0241659 to Ashcraft et al., each of which is incorporated by reference herein. The nanocellulose may be applied alone and/or in combination with other materials used in ignition-propensity-reduction coatings and may be applied in any pattern effective for that purpose. The use of nanocellulose in accordance with the present disclosure will be useful for those types of cigarette filter technologies set forth in U.S. Pat. No. 7,115,085 to Deal; U.S. Pat. No. 7,479,098 to Thomas et al.; U.S. Pat. No. 7,836,895 to Dube et al.; U.S. Pat. No. 8,186,359 to Ademe et al.; U.S. Pat. No. 8,262,550 to Barnes et al.; and U.S. Pat. No. 8,308,623 to Nelson et al.; and U.S. Pat. App. Pub. Nos. 2008/0142028 to Fagg; 2011/0232658 to Dube et al.; and 2012/0298120 to Barnes et al, each of which is incorporated herein by reference.

It should be appreciated that nanocellulose may be used in the foregoing manner in the construction of segmented smoking articles, including—for example—smoking articles that generate flavored vapors by subjecting tobacco or processed tobacco(s) to heat produced from chemical or electrical heat sources rather than (and/or in addition to) combustion of tobacco or processed tobacco(s). Examples include devices disclosed in U.S. Pat. No. 5,285,798 to Banerjee et al.; U.S. Pat. No. 7,290,549 to Banerjee et al.; U.S. Pat. No. 7,836,897 to Borschke et al.; U.S. Pat. App. Pub. Nos. 2008/0092912 to Robinson et al.; 2012/0067360 to Conner et al. filed Sep. 20, 2011; 2012/0042885 to Stone et al.; and 2011/0271972 to Thomas et al., each of which is incorporated by reference herein in its entirety.

Referring to FIG. 4, an embodiment of a smoking article 210 in the form of a cigarette is shown. The smoking article 210 has a rod-like shape, and includes a lighting end 214 and a mouth end 218.

A longitudinally extending, generally cylindrical smokable lighting end segment 222 incorporating a smokable material 226 is positioned at the lighting end 214. A representative smokable material 226 can be a plant-derived material (e.g., tobacco material in cut filler form). An exemplary cylindrical smokable lighting end segment 222 includes a charge or roll of the smokable material 226 (e.g., tobacco cut filler) wrapped or disposed within, and circumscribed by, a paper wrapping material 230. The smokable lighting end segment 222 may be configured so that smokable material 226 and wrapping material 230 each extend along the entire length thereof.

A longitudinally extending, generally cylindrical heat generation segment 235 is located downstream from the smokable lighting end segment 222. The heat generation segment 235 includes a heat source 240 circumscribed by insulation 242, which may be coaxially encircled by wrapping material 245. The heat source 240 preferably is configured to be activated by combustion of the smokable material 226. Ignition and combustion of the smoking material preferably provide a user with a desirable experience (with respect at least to flavor and time taken to light the smoking article 210). The heat generated as the smokable material is consumed most preferably is sufficient to ignite or otherwise activate the heat source 240.

A representative substrate wrapping material 258 for the substrate material 255 may include heat conductive properties to conduct heat from the heat generation segment 235 to the aerosol-generating segment 251, in order to provide for the volatilization of the aerosol forming components contained therein.

The substrate material 255 can be provided from a blend of flavorful and aromatic tobaccos in cut filler form, whether as a tobacco rod or other form. Those tobaccos, in turn, can be treated with aerosol-forming material and/or at least one flavoring agent. The substrate material can be provided from a processed tobacco (e.g., a reconstituted tobacco manufactured using cast sheet or papermaking types of processes) in cut filler form, in marumarized form, aggregated as pellets, or any other appropriate form. Certain cast sheet constructions may include about 270 to about 300 mg of tobacco per 10 mm of linear length. That tobacco, in turn, can be treated with, or processed to incorporate, aerosol-forming material and/or at least one flavoring agent, as well as a burn retardant (e.g., diammonium phosphate or another salt) configured to help prevent ignition and/or scorching by the heat-generation segment. A metal inner surface provided on the substrate wrapping material 258 of the aerosol-generating segment 251 can act as a carrier for aerosol-forming material and/or at least one flavoring agent as well as transmitting heat longitudinally in the device. Generally, the tobacco material is heated but not burned during use of the smoking article 210.

In other embodiments, the substrate 255 may include a tobacco paper or non-tobacco gathered paper formed as a plug section, which may be loaded with aerosol-forming materials, flavorants, tobacco extracts, or the like in a variety of forms (e.g., microencapsulated, liquid, powdered). A burn retardant (e.g., diammonium phosphate or another salt) may be applied to at least a distal/lighting-end portion of the substrate to help prevent ignition and/or scorching by the heat-generation segment. For preferred smoking articles, both ends of the aerosol-generating segment 251 are open to expose the substrate material 255 thereof. Components of the aerosol produced by burning the smokable lighting end segment 222 during use of the smoking article can readily pass through the aerosol-generating segment 251 during draw on the mouth end 218.

Together, the heat generating segment 235 and the aerosol-generating segment 251 form an aerosol-generation system 260. The aerosol-generating segment 251 is positioned adjacent to the downstream end of the heat generation segment 235 such that those segments 251, 235 are axially aligned in an end-to-end relationship. Those segments can abut one another, or be positioned in a slightly spaced apart relationship, which may include a buffer region 253. A buffer region 253 may reduce potential scorching or other thermal degradation of portions of the aerosol-generating segment 251. The buffer region 253 may mainly include empty air space, or it may be partially or substantially completely filled with a non-combustible material such as, for example, metal, organic, inorganic, ceramic, or polymeric materials, or any combination thereof.

The components of the aerosol-generation system 260 and the smokable lighting end segment 222 preferably are attached to one another, and secured in place using an overwrap material 264. For example, the overwrap material 264 can include a paper wrapping material or a laminated paper-type material that circumscribes each of the heat generation segment 235, at least a portion of outer longitudinally extending surface of the aerosol-generating segment 251, and at least a portion of an the lighting end segment 222 that is adjacent to the heat generation segment. The inner surface of the overwrap material 264 may be secured to the outer surfaces of the components it circumscribes by a suitable adhesive. Preferably, the overwrap material 264 extends over a significant portion of the length of the smokable lighting end segment 222.

The smoking article 210 preferably includes a suitable mouthpiece such as, for example, a filter element 265, positioned at the mouth end 218 thereof. The filter element 265 preferably is positioned at one end of the cigarette rod adjacent to one end of the aerosol-generating segment 251, such that the filter element 265 and the aerosol-generating segment 251 are axially aligned in an end-to-end relationship, abutting one another but without any barrier therebetween. The filter element 265 may include filter material 270 that is overwrapped along the longitudinally extending surface thereof with circumscribing plug wrap material 272. In one example, the filter material 270 includes plasticized cellulose acetate tow, while in some examples the filter material may further include activated charcoal in an amount from about 20 to about 80 mg disposed as a discrete charge or dispersed throughout the acetate tow in a “Dalmatian type” filter. The aerosol-generating system 260 preferably is attached to filter element 265 using tipping material 278. The smoking article 210 may include an air dilution means, such as a series of perforations 281, each of which may extend through the filter element tipping material 278 and plug wrap material 272 in the manner shown, and/or which may extend to or into the substrate 255.

The filter element 265 may also include a crushable flavor capsule 276 of the type described in U.S. Pat. No. 7,479,098 to Thomas et al.; U.S. Pat. No. 7,793,665 to Dube et al. and U.S. Pat. App. Pub. No. 2009/0194118 to Ademe et al., which are incorporated herein by reference in their entirety. In the same manner as described above, a nanocellulose barrier may be provided on one or both sides of the plug wrap and/or the tipping material, on an external surface of the filter material, and/or an interface between the filter material and plug wrap. Preferably, the nanocellulose is applied on an outward-facing surface of the plug wrap, on an inward-facing surface of the tipping material, and/or an interface therebetween.

Referring to FIG. 5, a representative smoking article 310 in the form of a cigarette is shown. The smoking article 310 includes a heat generation segment 335 located at the lighting end 314, a filter segment 365 located at the other end (mouth end 318), and an aerosol-generating segment 351 (which may incorporate tobacco) that is located in between those two segments near the lighting end. The heat generation segment 335 of FIG. 5 can incorporate a generally cylindrical carbonaceous heat source circumscribed by insulation similar to what is shown in FIG. 4. The composition and dimensions of the various segments of the smoking article 310 in FIG. 5 are generally similar in manner with respect to those set forth previously with reference to FIG. 4, but without a charge of smokable material at the distal/lighting end, such that the fuel element is ignited directly rather than by a smokable material that was ignited and burned. This includes that any drawing numbers (3xx) not referenced specifically herein designate components corresponding to like reference numbers (2xx) in FIG. 4 and will be understood as such by those of skill in the art (e.g., capsule 276 corresponds to capsule 376, even though the latter is not explicitly referenced above).

Those of skill in the art will appreciate that embodiments not expressly illustrated herein may be practiced within the scope of the claims, including that features described herein for different embodiments may be combined with each other and/or with currently-known or future-developed technologies while remaining within the scope of the claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation unless specifically defined by context, usage, or other explicit designation. It is therefore intended that the foregoing detailed description be regarded as illustrative rather than limiting. And, it should be understood that the following claims, including all equivalents, are intended to define the spirit and scope of this invention. Furthermore, the advantages described above are not necessarily the only advantages of the invention, and it is not necessarily expected that all of the described advantages will be achieved with every embodiment. 

We claim:
 1. A smoking article, comprising: a lighting end longitudinally opposite a filter end that includes a filter; a fluid-releasing element disposed longitudinally between the lighting end and filter end; a paper material circumscribing a portion of the smoking article, and a nanocellulose barrier disposed upon at least one surface or interface within the smoking article between the a fluid-releasing element and the paper material, where the barrier is effective to control passage of fluid through the paper material.
 2. The smoking article of claim 1, where the paper material includes plug wrap circumscribing at least a portion of filter material.
 3. The smoking article of claim 2, where the fluid-releasing element includes a fluid-releasing capsule within the filter, and the nanocellulose barrier is disposed upon a surface of the plug wrap and is effective to prevent passage of fluid through the plug wrap.
 4. The smoking article of claim 1, comprising a filter material where at least a portion of the nanocellulose barrier is disposed on an exterior-facing surface of the filter material.
 5. The smoking article of claim 4, where the filter material includes the fluid-releasing element, which comprises at least one fluid-releasing capsule, and the nanocellulose barrier is effective to prevent passage of fluid out of the filter material through the paper material.
 6. The smoking article of claim 1, where the paper material is configured as wrapping material circumscribing a tobacco rod portion of the smoking article and where the nanocellulose barrier is also distributed on the wrapping material sufficiently restricting airflow therethrough in a manner effective to limit combustion of the tobacco rod in the absence of air being drawn through the tobacco rod.
 7. The smoking article of claim 1, where the paper material includes tipping material circumscribing at least a portion of filter material.
 8. The smoking article of claim 7, where the fluid-releasing element includes a fluid-releasing capsule within the filter, and the nanocellulose barrier is disposed upon a surface of the tipping material and is effective to prevent passage of fluid through the tipping material.
 9. A smoking article, comprising: a lighting end that includes a tobacco rod disposed longitudinally opposite a filter end that includes a filter; a fluid-releasing element disposed within the filter; a paper wrapping material circumscribing the tobacco rod, a plug wrap material circumscribing the filter; and a nanocellulose barrier circumscribing the filter, effective to control passage of fluid through the barrier.
 10. The smoking article of claim 9, further comprising tipping material circumscribing the plug wrap material and at least a portion of the paper wrapping material circumscribing the tobacco rod.
 11. The smoking article of claim 10, where the nanocellulose barrier is disposed upon a surface of the plug wrap material facing the filter.
 12. The smoking article of claim 10, where the nanocellulose barrier is disposed in an interface between the plug wrap material and the tipping material.
 13. The smoking article of claim 9, where the nanocellulose barrier is disposed upon a surface of the plug wrap material at a density of about 1 gram/meter² to about 5 grams/meter².
 14. The smoking article of claim 9, where the nanocellulose barrier comprises nanocellulose fibers that are about 1 to about 2 micrometers in length and about 5 to about 20 nanometers in diameter.
 15. The smoking article of claim 9, further comprising at least one low-ignition-propensity region circumscribing the tobacco rod, where the at least one low-ignition-propensity region comprises nanocellulose material.
 16. The smoking article of claim 9, where one or more of a heat generation segment, an aerosol-generating segment, and a buffer region are disposed between the lighting end and the filter.
 17. The smoking article of claim 9, where the nanocellulose barrier comprises nanocellulose fibers that include a length to width ratio of at least 10:1.
 18. The smoking article of claim 9, where the nanocellulose barrier comprises nanocellulose fibers that include a length to width ratio of at least 100:1.
 19. A smoking article, comprising: a lighting end that includes a tobacco rod disposed longitudinally opposite a filter end that includes a filter; a fluid-releasing flavor capsule disposed within the filter; a paper wrapping material circumscribing the tobacco rod, a plug wrap material circumscribing the filter; a nanocellulose barrier coating disposed upon at least one surface of the plug wrap circumscribing the filter, said barrier effective to control passage of fluid through the barrier; and tipping material circumscribing the plug wrap materials.
 20. The smoking article of claim 19, where the nanocellulose barrier comprises nanocellulose fibers that are about 1 to about 2 micrometers in length and about 5 to about 20 nanometers in diameter.
 21. The smoking article of claim 19, where one or more of a heat generation segment, an aerosol-generating segment, and a buffer region are disposed between the lighting end and the filter, and where the smoking article is configured for heating but not burning the tobacco rod during use. 